Zoom lens barrel

ABSTRACT

A lens control apparatus having a zoom lens includes first and second operation members that give a zoom instruction for moving the zoom lens, and a controller that changes a zoom stop position to a first pattern according to the operation of the first operation member, and changes the zoom stop position to a second pattern, which has an interval wider than that in the first pattern, according to the operation of the second operation member.

This application is a Continuation of co-pending U.S. patent applicationSer. No. 14/267,640 filed May 1, 2014, which claims priority from U.S.patent application Ser. No. 13/894,195 filed May 14, 2013 which hasissued as U.S. Pat. No. 8,749,895, which claims priority from U.S.patent application Ser. No. 12/852,255 filed Aug. 6, 2010 which hasissued as U.S. Pat. No. 8,462,445, which claims the priority benefit ofJapanese Patent Application No. 2009-188821 filed Aug. 18, 2009. Thedisclosures of the above-described applications are hereby incorporatedby reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus, and moreparticularly to a technique of enhancing operability when a focal lengthor an angle of view of a captured image is changed in an imagingapparatus having a zoom function.

2. Description of the Related Art

Japanese Patent Application Laid-Open No. 2-68507 discusses thatconventional imaging apparatuses having a zoom lens include the one inwhich a zoom mode continuously changes the focal length and the other inwhich a zoom mode stepwisely changes a predetermined focal length, whena focal length of the zoom lens is changed.

However, when a user intends to take a photo with the specific focallength such as 28 mm, 35 mm, or 50 mm, which is generally used for ashort focal lens of a camera, the problem described below arisesaccording to the technique discussed in Japanese Patent ApplicationLaid-Open No. 2-68507. Namely, correctly adjusting the focal length tothe desired one is not easy in the zoom mode that continuously changesthe focal length. Further, in the zoom mode that stepwisely changes thefocal length, the user has to keep depressing a zoom operation switch orto depress the same switch a plurality of times until the user sets thefocal length to the desired one. Further, when the focal length, that isstepwisely changed, does not have a desired angle of view, and a userintends to perform fine adjustment, the user has to change the mode tothe zoom mode that continuously changes the focal length, and then, theuser has to perform again the zoom operation.

SUMMARY OF THE INVENTION

The present invention includes the first zoom control mode and thesecond zoom control mode. Therefore, the zoom position can be changeddesignating the specific focal length and angle of view, and further,the angle of view can easily and finely be adjusted to a desired one.Accordingly, operability when changing a focal length or an angle ofview of the imaging apparatus, can be enhanced.

According to an aspect of the present invention, a lens controlapparatus having a zoom lens includes first and second operation membersthat give a zoom instruction for moving the zoom lens, and a controllerthat changes a zoom stop position to a first pattern according to theoperation of the first operation member, and changes the zoom stopposition to a second pattern, which has an interval wider than that inthe first pattern, according to the operation of the second operationmember.

Further features and aspects of the present invention will becomeapparent from the following detailed description of exemplaryembodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate exemplary embodiments, features,and aspects of the invention and, together with the description, serveto explain the principles of the invention.

FIGS. 1A, 1B, and 1C are a block diagram illustrating a configuration ofan imaging apparatus and diagrams illustrating a zoom operation memberaccording to one exemplary embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating a display screen of theimaging apparatus in performing the zoom operation according to oneexemplary embodiment of the present invention.

FIGS. 3A and 3B are diagrams illustrating an operation for changing thezoom position of the imaging apparatus according to one exemplaryembodiment of the present invention.

FIG. 4 is a flowchart illustrating the zoom operation of the imagingapparatus according to one exemplary embodiment of the presentinvention.

FIGS. 5A and 5B are flowcharts illustrating the zoom operation of theimaging apparatus according to one exemplary embodiment of the presentinvention.

FIGS. 6A and 6B are flowcharts illustrating the zoom operation of theimaging apparatus according to one exemplary embodiment of the presentinvention.

FIG. 7 is a flowchart illustrating the zoom operation of the imagingapparatus according to another exemplary embodiment of the presentinvention.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the inventionwill be described in detail below with reference to the drawings.

The present invention will now be described in detail below withreference to the accompanying drawings illustrating embodiments thereof.

An important point of the present invention is that the presentinvention includes the above first and second zoom control modes.Typically, the control mode can be changed to the first zoom controlmode according to the operation of the first operation member, and thecontrol mode can be changed to the second zoom control mode according tothe operation of the second operation member. When the zooming isexecuted by the optical zooming in the zoom control mode, it can bedetermined from the viewpoint of the control position of the zoom lensthat by the operation member, the zoom position can be changed in afirst pattern or in a designated manner. When the zooming is executed byan electronic zooming in the zoom control mode, it can be determinedfrom the viewpoint of the angle of view of a captured image on a displayunit that by the operation member, the angle of view of the capturedimage can be changed according to the first pattern or in a directlydesignated manner.

Based on such a thought, the basic form of the imaging apparatusaccording to the present invention includes the above configuration. Theexemplary embodiments described below are possible based on the basicform. For example, the zoom position is continuously or stepwiselyarranged in the first pattern (refer to a first exemplary embodimentdescribed below). A control unit can change the zoom speed depending onthe member being operated of the first and second operation members(refer to a second exemplary embodiment described below). In this case,the control unit typically increases the zoom speed in the second zoomcontrol mode compared with the zoom speed in the first zoom controlmode. When the second operation member is operated during the electroniczooming, the control unit cancels the electronic zooming, and can changethe zoom position only by the optical zooming (refer to a thirdexemplary embodiment described below).

An exemplary embodiment of the present invention will be described indetail with reference to the attached drawings.

A configuration and operation of an imaging apparatus according to afirst exemplary embodiment of the present invention will be describedwith reference to FIGS. 1 to 6. FIG. 1A is a block diagram illustratingthe configuration of an imaging apparatus 100, which is represented by adigital camera and to which the present invention can be applied. Asystem control unit 101 serving as a control unit controls the wholeimaging apparatus 100. A zoom lens 102 changes a focal length bychanging the position thereof in an optical axis direction. A zoomcontrol unit 103 performs control to drive the zoom lens 101. Ashutter/diaphragm control unit 105 performs control to drive ashutter/diaphragm unit 104. A focus lens 106 changes its position in theoptical axis direction to perform focus adjustment. A focus control unit107 performs control to drive the focus lens 106. An image sensor 108converts an optical image passing through respective lenses into anelectric signal. A signal processing unit 109 converts the electricsignal output from the image sensor 108 into a video signal, andprocesses the resultant signal according to a purpose.

A display unit or a notification unit 110 includes a liquid crystaldisplay device, speakers, and the like. The display unit or thenotification unit 110 displays or notifies an operation state or amessage using a character, an image, voice, etc. based on the executionof a program at the system control unit 101 or a signal output from thesignal processing unit 109. An operation unit 111 includes variousbuttons, and inputs an instruction of various operations to the systemcontrol unit 101. A storage unit 112 is a memory that stores variouspieces of data such as a constant, variable, a program, or videoinformation for operating the system control unit 101. A recording unit113 is a non-volatile memory that can electrically erase or recordphotographing data. A power source unit 114 supplies power source to thewhole imaging apparatus 100 according to its purpose.

Next, an operation of the imaging apparatus thus configured will bedescribed. The operation unit 111 has a shutter release buttonconfigured such that a first switch (hereinafter referred to as SW1) anda second switch (hereinafter referred to as SW2) are successively turnedon according to the depression amount. When the shutter release buttonis half depressed, the SW1 is turned on, while the SW2 is turned on whenthe shutter release button is fully depressed. When the SW1 on theoperation unit 111 is turned on, the system control unit 101 drives thefocus lens 106 by the focus control unit 107 carrying out an AF(autofocus) function to perform focus adjustment. Simultaneously, thesystem control unit 101 drives the shutter/diaphragm unit 104 by theshutter/diaphragm control unit 105 carrying out an AE function to set anexposure amount to an appropriate amount. When the SW2 is turned on, thesystem control unit 101 converts the electric signal, which is obtainedfrom the image sensor 108 that is exposed to the optical image, into animage signal at the signal processing unit 109 to perform an imageprocess, and then, stores the resultant signal in the storage unit 112.Simultaneously, the system control unit 101 records image data onto arecording medium at the recording unit 113.

The operation unit 111 includes a zoom wide button 200 and a zoomtelephoto button 201, which are first operation members, illustrated inFIG. 1B. When the zoom button on the operation unit 111 is turned on,the system control unit 101 drives the zoom lens 102 by the zoom controlunit 103 in the direction according to the zoom button that is turnedon. When the zoom button is turned off, it stops the drive of the zoomlens 102. Specifically, the zoom button that is the first operationmember executes a first zoom control mode through the system controlunit 101, in which a zoom position is arranged (continuously orstepwisely) as a first pattern within the range between a wide-angle endand a telephoto end. In this case, the system control unit 101 displaysthe drive state of the zoom lens 102 as illustrated in FIG. 2A. FIG. 2Aillustrates one example of a liquid crystal display (LCD) display, andshows where the zoom position is positioned between the wide-angle endand the telephoto end.

The operation unit 111 further includes a zoom ring 202 that is a secondoperation member illustrated in FIG. 1C. When the zoom ring 202 isturned, the system control unit 101 moves the zoom lens 102 to the focallength designated according to the turning amount of the ring by thezoom control unit 103. Specifically, the zoom ring that is the secondoperation member executes a second zoom control mode through the systemcontrol unit 101, in which a zoom position (here, the focal length) thatcan be changed and is arranged as a second pattern rougher than thefirst pattern, is designated. The zoom position is designated in thesecond zoom control mode as the pattern rougher than the pattern of thezoom position, at which the zooming can be stopped in the first zoomcontrol mode. For example, when as the pattern in the second zoomcontrol mode, the positions corresponding to the focal length of 28 mm,35 mm, and 50 mm can be designated, the pattern in the first zoomcontrol mode is as follows. Specifically, in the first zoom controlmode, the pattern is set such that zooming can be stopped at one or aplurality of positions between 28 mm and 35 mm, and zooming can bestopped at one or a plurality of positions between 35 mm and 50 mm. Inother words, the pattern in the first zoom control mode is denser thanthat in the second zoom control mode. In this case, it may be configuredsuch that the zooming can be stopped at the position corresponding tothe focal length shorter than 28 mm, or at the position corresponding tothe focal length longer than 50 mm. At this time, the system controlunit 101 displays the target focal length on the display unit 110 suchas LCD according to the turning amount of the zoom ring 202 asillustrated in FIG. 2B. The focal length displayed on the display unit110 is the specific focal length, such as 28 mm, 35 mm, and 50 mm, whichare generally used for a short focal camera lens in the exampledescribed above.

When driving the zoom lens, the system control unit 101 drives the focuslens 106 by the focus control unit 107 based on the image information,which is sent from the image sensor 108 and processed at the signalprocessing unit 109, to perform the focus adjustment. The focusadjustment is performed here according to a so-called hill climbingmethod, for example. On the other hand, the focus adjustment when theSW1 is turned on, is performed such that scan is performed with thefocus lens within a constant range to obtain an AF evaluation value, andthen, the focus lens is moved to the maximum AF evaluation value.

The zoom operation of the imaging apparatus according to the presentexemplary embodiment will be described with reference to FIGS. 4 to 6.In FIG. 4, the system control unit 101 determines in step S500 whetherthe zooming is executed with the focal length designated (the abovesecond zoom control mode). If the zooming is not executed with thedesignated focal length, the system control unit 101 executes a normalzoom drive (the above first zoom control mode) in step S501.

The normal zoom drive process will be described with reference to FIG.5A. In step S600, the system control unit 101 determines whether thezoom wide button 200 or the zoom telephoto button 201 is turned on. Ifthe zoom button is not turned on (NO in step S600), the system controlunit 101 ends the normal drive process. If the zoom button is turned on(YES in step S600), the system control unit 101 determines whether thezoom button turned on is the zoom wide button 200 or the zoom telephotobutton 201 in step S601. When the wide button is turned on (wide buttonin step S601), the system control unit 101 sets a zoom target positionto the wide-angle end in step S602. On the other hand, when thetelephoto button is turned on (telephoto button in step S601), thesystem control unit 101 sets a zoom target position to be the telephotoend in step S603. The zoom target position is stored in the storage unit112.

Next, in step S604, the system control unit 101 determines whether thezooming is executed. If the zooming is not executed (NO in step S604),the system control unit 101 starts the zooming in the direction towardthe set target position in step S605, and then, ends the normal driveprocess. On the other hand, if the zooming is executed (YES in stepS604), the system control unit 101 executes a process of changing thetarget position in step S606, and then, ends the normal drive process.The detail of the process of changing the target position will bedescribed below with reference to FIG. 6B. The normal zoom drive processhas been described above.

Returning to FIG. 4, when the zooming is executed with the focal lengthdesignated in step S500 or when the normal zoom drive process in stepS501 is ended, the system control unit 101 determines whether thezooming is executed in the normal drive in step S502. If the zooming isnot executed in the normal drive (NO in step S502), the system controlunit 101 executes a zoom drive process with the focal length designated.

The zoom drive process with the focal length designated will bedescribed with reference to FIG. 5B. In step S700, the system controlunit 101 determines whether the zoom ring 202 is turned. If the zoomring is not turned (NO in step S700), the system control unit 101 endsthe drive process with the designated focal length. When the zoom ringis turned (YES in step S700), the system control unit 101 acquires thefocal length designated according to the turning amount of the zoom ringin step S701. As illustrated in FIG. 3B, the designated focal length isthe specific focal length according to the turning amount of the zoomring 202, regardless of the current position of the zoom lens 102.

Next, in step S702, the system control unit 101 sets the zoom targetposition to the focal length acquired in step S701. The zoom targetposition is stored in the storage unit 112. Then, in step S703, thesystem control unit 101 determines whether the zooming is executed. Ifthe zooming is not executed (NO in step S703), the system control unit101 starts the zooming in the direction toward the set target positionin step S704, and then, ends the drive process with the designated focallength. On the other hand, when the zooming is executed (YES in stepS703), the system control unit 101 executes the process of changing thetarget position in step S705, and then, ends the drive process with thefocal length designated. The process of changing the target positionwill be described below with reference to FIG. 6B. The drive processwith the designated focal length has been described above.

Returning again to FIG. 4, when the zooming is executed in the normaldrive in step S502 or when the drive process with the focal lengthdesignated in step S503 is ended, the system control unit 101 executes azoom stop process in step S504, and then, the processing returns to stepS500 to repeat the process.

The zoom stop process will be described with reference to FIG. 6A. Instep S800, the system control unit 101 acquires the current zoomposition. Next, in step S801, the system control unit 101 determineswhether the zoom button is changed from the on-state to the off-state.When the zoom button is not changed from the on-state to the off-state(NO in step S801), the processing proceeds to step S805. When the zoombutton is changed from the on-state to the off-state (YES in step S801),the system control unit 101 determines in step S802 the stop positionbased on the current zoom position acquired in step S800. As illustratedin FIG. 3A, the stop position is determined to be the zoom positionshifted in the current drive direction from the current zoom position.Although the zoom position is stepwisely illustrated in FIG. 3A, theposition where the zooming can be stopped may also be the continuousoptional position.

In step S803, the system control unit 101 sets the zoom target positionto be the stop position determined in step S802. The zoom targetposition is stored in the storage unit 112. Then, in step S805, thesystem control unit 101 determines whether the zooming has reached thetarget position stored in the storage unit 112 based on the current zoomposition acquired in step S800. When the zooming has not reached thetarget position (NO in step S800), the system control unit 101 ends theprocess of stopping the zooming. On the other hand, when the zooming hasreached the target position (YES in step S800), the system control unit101 stops the drive of the zoom in step S806, and then, ends the processof stopping the zooming. The process of stopping the zooming has beendescribed above.

Finally, the process of changing the target zoom position will bedescribed with reference to FIG. 6B. In step S900, the system controlunit 101 acquires the current zoom position. Then, in step S901, thesystem control unit 101 determines whether the target position stored inthe storage unit 112 is located in the reverse direction of the currentdrive direction relative to the current position. When the targetposition is not in the reverse direction (NO in step S901), the systemcontrol unit 101 ends the process of changing the target zoom position.On the other hand, when the target position is in the reverse direction(YES in step S901), the system control unit 101 reverses the zooming instep S902, and then, ends the process of changing the target zoomposition. The process of changing the target zoom position has beendescribed above.

As described above, according to the present exemplary embodiment, thespecific focal length is directly designated by the zoom operation usingthe zoom ring, which is the second operation member, whereby the focallength of the zooming can be changed. With this, an angle of view can beadjusted to the desired one by the zoom operation using the zoom buttonthat is the first operation member. Accordingly, the zoom operationaccording to a photographing scene or a subject can be comfortablycarried out, whereby operability in changing the focal length of theimaging apparatus can be enhanced.

In the first exemplary embodiment, the zoom speed may be changedaccording to the operation member. The second exemplary embodiment is anexample of executing the changeover as described above. In the secondexemplary embodiment, in the case of the zooming by the zoom button(first zoom control mode), the zoom drive speed is set to be low whenthe zooming is started toward the target position in step S605 in FIG.5A. In the case of the zooming by the zoom ring (second zoom controlmode), the zoom drive speed is set to be high when the zooming isstarted toward the target position in step S704 in FIG. 5B. Thus, sincethe zoom speed is increased in the zoom operation by the zoom ring, thefocal length can promptly be changed to the desired one. On the otherhand, since the zoom speed is decreased in the zoom operation by thezoom button, fine adjustment of the angle of view can correctly beperformed.

In the first exemplary embodiment, the electronic zooming may becanceled when the zoom ring is operated during the electronic zooming. Athird exemplary embodiment illustrates this example. A zoom operation ofan imaging apparatus according to the third exemplary embodiment will bedescribed with reference to FIG. 7. Steps S1000, and S1003 to S1007 inFIG. 7 in a flowchart illustrating the zoom operation of the imagingapparatus in the present exemplary embodiment are the same as steps S700and S701 to S705 in FIG. 5B. If the device is in the electronic zoomoperation in step S1001 in FIG. 7, the system control unit 101 cancelsthe electronic zooming in step S1002, and the processing proceeds tostep S1003.

As described above, in the present exemplary embodiment, when the zoomring, which is the second operation member, is operated during theelectronic zooming, the electronic zooming is canceled, whereby thefocal length can easily be set to the desired one.

As illustrated in the third exemplary embodiment, the zoom function canbe executed by the electronic zooming. As one example, the zoom lens ismoved to execute an optical zooming up to a predetermined focal length,and the zoom function afterward is executed by the electronic zooming.Specifically, the zoom function can be executed by at least one of theoptical zooming and the electronic zooming.

The preferable exemplary embodiments of the present invention have beendescribed above. However, the present invention is not limited to thespecific exemplary embodiments described above, and includes variousmodifications without departing from the scope of the invention. Some ofthe above exemplary embodiments may appropriately be combined. Thepresent invention also includes the case in which a software programthat realizes the function of the above exemplary embodiments isdirectly supplied from a recording medium, or is supplied through wiredcommunication/wireless communication, to a system or a device, which hasa computer that can execute the program, to execute the program.Therefore, a program code that can be supplied and installed in thecomputer to realize the functional process (the function executed by theabove control unit) of the present invention realizes the presentinvention. Specifically, the present invention also includes thecomputer program that realizes the functional process of the presentinvention. In this case, any program form can be selected, such as anobject code, a program executed by an interpreter, or script datasupplied to OS, as long as it has a function of the program. Examples ofusable recording medium for supplying the program include a magneticrecording medium such as a hard disk or a magnetic tape, anoptical/magneto-optical recording medium, or non-volatile semiconductormemory. As the method for supplying the program, a server on a computernetwork may store the computer program constituting the presentinvention, and a client computer connected to the computer networkdownloads the computer program to code the program.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures, and functions.

What is claimed is:
 1. A lens control apparatus having a zoom lenscomprising: a first operation member that gives a zoom instruction by anoperator for moving the zoom lens; a second operation member that givesa zoom instruction by the operator for moving the zoom lens, wherein thesecond operation member is different from the first operation member andthe second operation member is able to rotate around an optical axis ofthe zoom lens; and a controller that controls the zoom lens to move atleast from a first position to a second position at a first speed in acase where the first operation member is operated, and at a second speedin a case where the second operation member is operated, wherein thesecond speed is faster than the first speed.
 2. The lens controlapparatus according to claim 1, wherein the controller changes a zoomposition with a first pattern in response to the operation of the firstoperation member, and changes a zoom position with a second pattern,which has a pitch wider than that in the first pattern, in response tothe operation of the second operation member.
 3. The lens controlapparatus according to claim 1, wherein the first operation memberincludes a zoom telephoto button for moving the zoom lens toward atelephoto side and a zoom wide button for moving the zoom lens toward awide side.
 4. The lens control apparatus according to claim 1, whereinthe second operation member is positioned nearer from the zoom lens thanthe first operation member.
 5. The lens control apparatus according toclaim 1, wherein the second operation member is positioned in front ofthe camera apparatus.
 6. The lens control apparatus according to claim1, wherein the second operation member is positioned in back of thecamera apparatus.